Keyboard pushbutton with character visible in depressed position



L. TIBBETTS 3,464,532

KEYBOARD PUSH LiTTON WITH C AC VISIBLE Sept. 2, 1969* IN DEPRESSED P0TIO Filed Aug. 30, 1967 V I so HO 120 loo 4 4 I00 I50 2.0 4 29,4

INVENTOR.

ERNEST L. TIBBETTS kfwf eg ATTORNEY.

United States Patent US. Cl. 197-98 9 Claims ABSTRACT OF THE DISCLOSUREThe disclosure is of a pushbutton for displaying a character and for usein displaying a number in a calculating instrument. The pushbuttonincludes a fixed post having an upper end on which a character isprinted or otherwise formed. A slidable sleeve member is slidablymounted on the post with its closed end parallel to and spaced above theend wall of the post. The sleeve member is made of a synthetic resinousmaterial which is opaque when it is of a certain thickness, and istransparent when it is suitably thin. The side wall of the sleeve issufficiently thick to be opaque, and the end wall is sufliciently thinso that, when it is depressed and it is placed close to the character,the character can be seen therethrough. When the sleeve is in itselevated position, the character on the fixed post cannot be seen.

The disclosure is also of a pushbutton assembly in which the sleeve ofthe pushbutton is provided with a wedge-shaped locking tab which engagesan upper horizontal plate when the sleeve is in its elevated position.The assembly also includes a pivotable plate positioned between theupper plate and base plate for engaging the locking tab and holding thesleeve in its lowered position.

Background of the invention There are many types of pushbuttons known inthe prior art for displaying characters such as numerals, letters, orthe like. However, either the character is always clearly visiblethrough the pushbutton, or, as in one known type of pushbutton, thecharacter is dimly visible normally and is made clearly visible by arelatively complex combination of parts.

The present invention provides, in an extremely simple construction, .apushbutton which includes a fixed post having an upper end which carriesthe character to be displayed. A slidable sleeve is mounted on the post,and the sleeve has a closed end which is used as a viewing windowthrough which the character is to be viewed. Means are provided to holdthe sleeve in an elevated position in which the character is not viewedor in a lowered position in which the character is viewed. To this end,the sleeve is made of a material, the transparency of which isdetermined by its thickness and the closed end or viewing window issufficiently thin so that, when the sleeve is in its naised position,the character either cannot be seen at all, or it can be seen onlydimly. However, when the sleeve is in its lowered position and theclosed end is close to the character, the character can be seen clearly.

Description of the drawing In the drawing:

FIG. 1 is a sectional elevational view of a pushbutton and mountingassembly therefor according to the invention;

FIG. 2 is a sectional elevational view of the pushbutton of FIG. 1 as itappears in use; and

"ice

FIG. 3 is a sectional elevational view of a modification of a portion ofthe invention; and

FIG. 4 is a plan view of the invention.

Description of the preferred embodiments The pushbutton 10 of theinvention includes a fixed post 20 of a synthetic resinous material,metal, or the like, which is secured to a suitable support base 30 andincludes an upper end wall 40. The character 50 to be viewed ordisplayed is formed on the upper end wall 40 in any suitable fashion,for example, by painting, spraying, silk-screening, etc. In a modifiedarrangement (FIG. 3), the character 25 is formed on resilient pad 42 offoam rubber or the like secured to the end wall 40 of post 20. Thepushbutton 10 also includes a slidable sleeve 60 which comprises atubular body 70 and a closed end or viewing window The sleeve 65 isslidably mounted on the post 20 and is held in a normally raisedposition by means of a spring which is threaded on the post 20 and restson base plate 30'. The open lower end of the sleeve 60 rests on thespring 90. The sleeve 60 also includes a locking means in the form of awedge-shaped tab 100, by means of which the sleeve is adapted to belocked in either its raised or lowered positions. The locking taboriginates at a convenient location on the outer surface of sleeve 60and expands outwardly and upwardly toward closed end 80, and itterminates in a flat surface a suitable distance below end 80. One ormore tabs 100 may be provided, or the locking tab may be in the form ofa single annular tab extending around the entire periphery of thesleeve.

The sleeve member is preferably made of a synthetic resinous materialsuch as high density polyethylene, polyolefin, or the like which isopaque when suificiently thick and transparent when sufficiently thin.The side wall or main body 70 of the sleeve is thus preferably opaque.However, the closed end wall of the sleeve is a viewing window and isthus made relatively thin, for example, 45 to 50 mils, so that theviewer can see through it and so that, when the sleeve is depressed andthe closed end 80 is close to or in contact with the end wall 40 of thepost 20 (FIG. 2), the character 50 thereon can be viewed clearly throughthe end wall or viewing window 80 of the sleeve. When the sleeve is inits elevated position, the character either cannot be seen, or it can beseen only dimly.

In a typical arrangement for using one or more pushbuttons 10 in acalculating instrument or the like, an upper plate is provided spacedabove the base plate 30 and having apertures for receiving the slidablesleeves 60. The arrangement of parts is such that, when a button is notin use, the surface 110 of locking tab 100 bears against the lowersurface of upper plate 130, due to the upward force applied by spring90. Another locking plate for locking the sleeve 60 in its loweredposition comprises a pivot plate pivotally mounted on the base 30 bymeans of horizontal pin 132 suitably mounted and urged to the right, asseen in FIG. 1, by a spring 140. When the sleeve 60 is depressed, theramp or tapered portion of tab 100 forces the pivot plate 130 to theleft about its pivot point until the tab 100 is entirely beneath theupper locking edge 150* of plate 130. At this time, the spring urges thepivot plate 130 to the right, and spring 90 urges sleeve 60 upwardly tohold tab 100 in engagement with lip 150. The sleeve 60 is thus held inits lowered position, in which position the character 50 is clearlyvisible through its closed end 80.

What is claimed is:

1. A character displaying pushbutton assembly com- 3 prising a fixedpost mounted on a base plate and having an upper end wall,

a character to be viewed formed on said upper end wall of said fixedpost,

an apertured upper plate spaced above said base plate and having upperand lower surfaces,

a tubular sleeve slidably mounted on said post and positioned andslidably within an aperture in said apertured upper plate, said sleevehaving an open end which receives said post and a closed end Which isspaced above the end wall of said post and above said upper plate,

a coil spring mounted on said post beneath said sleeve and normallymaintaining said sleeve in an elevated non-displaying position withrespect to said post,

said sleeve also being adapted to compress said springlike member and toassume a. lowered characterdisplaying position with respect to saidpost,

the side wall of said sleeve being opaque and the closed end of saidsleeve being thin enough so that the character on said end wall of saidpost is clear- 1y visible through said closed end of said sleeve whenthe sleeve is in its lowered position and is not visible through saidclosed end when the sleeve is in its elevated non-displaying position,

said sleeve including a tubular side wall which carries a locking tabwhich bears against the lower surface of said apertured upper plate andthereby holds said sleeve in its elevated non-displaying position,

a second member pivotally mounted between said base plate and saidapertured plate adjacent to said fixed post and positioned to be engagedby said tab when said sleeve is in its lowered position to lock saidsleeve in its lowered position and pivotable to release said sleeve.

2. The apparatus defined in claim 1 wherein said second member comprisesa pivot plate having a lower edge and an upper edge, said plate beingpivotally mounted on said base on its lower edge whereby it can pivottoward and away from its pushbuttons about said lower edge, a springsecured to said pivot plate and urging it toward its pushbuttons, saidupper edge of said pivot plate comprising a locking member and adaptedto be engaged by said locking tab on a pushbutton, said locking tabbeing tapered and normally being positioned above said pivot plate, saidlocking tab being adapted to pivot said pivot plate away fromsaid sleeveas said sleeve is pushed downwardly whereby said locking tab can movevertically beneath said upper edge of said pivot plate and then saidspring can draw said pivot plate back toward said sleeve whereby itsupper edge can engage said locking tab beneath it.

3. A character displaying pushbutton comprising a fixed post having anupper end wall,

a character to be viewed formed on said upper end wall of said fixedpost,

a slidable tubular sleeve slidably mounted on said post, said sleevehaving an open end which receives said post and a closed end which isspaced above the end wall of said post,

a resilient, spring-like member in operative relation with said sleeveand normally maintaining said sleeve in an elevated non-displayingposition with respect to said post,

said sleeve also being adapted to compress said springlike member and toassume a lowered characterdisplaying position with respect to said post,

said sleeve including a tubular side wall which carries a locking tabwhich is adapted to lock said sleeve in its elevated displaying positionor in its lowered character-displaying position,

the side wall of said sleeve being opaque, and

the closed end of said sleeve being of the same material as said sidewall and of such thickness that when the sleeve is in its elevatedposition and said closed end is remote from the end wall of said post,said closed end appears to be opaque and a character on the end wall ofthe post cannot be seen, and, when the sleeve is in its lowered positionand its closed end is close to the end wall of said post, said closedend then appears to be transparent and a character on the end wall ofthe post can be seen.

4. The apparatus defined in claim 3 wherein said sleeve is made of highdensity polyethylene.

5. The pushbutton defined in claim 3 wherein said end wall and said sidewall of said sleeve member are of one piece and of the same material,said end wall being thinner than said side wall to permit viewing orsaid character therethrough when said sleeve is in its lowered position.

6. The device defined in claim 3 wherein said sleeve is made of asynthetic resinous material whose transparency is related to itsthickness, the material being opaque if it is sufficiently thick andtransparent if it is sufficiently thin, the side wall of the sleevebeing sufficiently thick to be opaque and the end wall beingsufficiently thin to be transparent enough so that said character can beviewed therethrough when the sleeve is in its lowered position.

7. The device defined in claim 3 wherein said character is painted onsaid end wall of said fixed post.

8. The device defined in claim 3 wherein said character is silk-screenedon said end wall of said fixed post.

9. The device defined in claim 3 wherein said locking tab tapersupwardly and outwardly from the wall of the sleeve toward the closed endthereof and terminates below said closed end in a generally flatsurface,

said flat surface being adapted to bear against a plate to hold saidsleeve in an elevated position, the taper of said tab permitting saidsleeve to move downwardly past a cooperating locking plate whereby saidflat surface can also engage said locking plate and hold said sleeve inits lowered position.

References Cited UNITED STATES PATENTS 1,286,769 12/1918 Quentell 235-XR 2,265,626 12/ 1941 Butler 235-145 2,642,226 6/1953 Luhn 235-4453,237,591 3/1966 Pichel 197102 XR 3,244,847 4/1966 Erpel 197-98 XR3,270,853 9/1966 Gerjets et a1. 197-98 3,311,210 3/1967 Peroni 197983,387,693 6/ 1968 Wirth 197--98 OTHER REFERENCES IBM TechnicalDisclosure Bulletin, vol. 6, No. 1. June 1963, p. 39, article by E. V.Weber entitled Changeable Keyboard Labeling and Coding.

EDGAR S. BURR, Primary Examiner US. 01. x11. 235-145; 197-102

